1. Field of the Invention
This invention is concerned with binders which releasably engage sheets of paper, plastic sleeves, and other materials, usually by apertures or notches in the materials. It is also concerned with books and the like which obtain benefit from pockets on their covers.
Specifically, the invention relates to an inexpensive and quick method of making a cover liner with a strong and wear resistant pocket.
2. Description of the Prior Art
Paper liners and pockets for paper covers are typically made in a succession of steps which include applying separate layers or folds to a cover and spot or line sealing of the layers, folds and cover with glue or adhesive.
Thermoplastic liners and pockets for plastic covers are also made in a succession of adding layers in which the assembled pieces are joined by fusing of adjacent thermoplastic surfaces by heat sealing or ultrasonic welding.
The methods are relatively slow and costly because they require several hand labor steps. For example, in fusing thermoplastic cover liners and pockets, the heat applicator shoe or ultrasonic horn has to apply energy in a specific pattern, and accurate alignment between the shoe or horn and the binder elements is necessary.
Another drawback is that tooling for assembling paper and thermoplastic cover liners and pockets is design specific, and must be changed to accommodate a change in design, such as a shape of a pocket on a cover of a binder.
The art is replete with patents for cover liners with pockets, and methods for making them.
For example, U.S. Pat. No. 2,105,232, patented Jan. 11, 1938 by F. S. Schade describes a method of forming a casing with a pocket, for a case-made looseleaf binder. The construction includes laying together plys of cardboard, perforating hinge rows and perforating adjacent rows in the cardboard through which cement is passed to cement together the ply panels and a metal stay which receives the ring mechanism. A strip of cardboard the width of a pocket is cemented to an outer edge of the inside face of the cover so that it is attached like a flap. A cover sheet is then placed on the outside face of the cover. Edges of the cover sheet are wrapped around three edges of the cover and are pasted down whereby they close over two more edges of the pocket flap. A single lining sheet is pasted over the inside face of the cover including the pocket. The opening of the pocket is then freed, or made accessible, by slitting the liner sheet.
U.S. Pat. No. 2,704,546, patented Mar. 22, 1955 by B. K. Slonneger describes a ring binder having a plastic sheet electrothermally sealed on three edges to the top, bottom and outer edge of a plastic cover of the binder, leaving the inward edge of the sheet free so that a pocket is formed which opens toward the binder rings at the center of the binder. To secure items which may be installed in the pocket, the free edge of the sheet includes an extension that is punched to fit on the rings.
Capturing the extension in the rings blocks the opening of the pocket. If leather, paper or other sheet material is used instead of plastic, stitching or gluing may be used instead of sealing by fusing.
U.S. Pat. No. 4,629,349, patented by W. R. Pitts, Dec. 16, 1986, describes a looseleaf notebook having two plastic sheets heat-sealed together at their left and right edges and their bottom edges to form between them a pocket that is opened at their top edges. A binder mechanism is mounted vertically at the center of the pocket by bolting through both sheets so that the pocket is divided into two pockets by the mechanism attachment.
Each pocket then becomes a cover for the notebook when they are folded together with the binder mechanism being the spine for the notebook.